Infantile myofibromatosis (MIM 228550) (“IM”) is one of the most common proliferative fibrous tumors of infancy and childhood. First described by Williams et al., “Congenital Fibrosarcoma: Report of a Case in a Newborn Infant,” AMA Arch. Pathl. 51:548-552 (1951) and Stout (Stout, “Juvenile Fibromatoses,” Cancer 7:953-978 (1954)), IM was further sub-categorized by others into solitary, multiple or generalized forms and shown to affect the skin, muscle, bone, and viscera (Kauffman et al., “Congenital Mesenchymal Tumors,” Cancer 18:460-476 (1965)). The term “infantile myofibromatosis” was recommended based on the fact that the cells have features of both differentiated fibroblasts and smooth muscle cells (myofibroblasts) (Chung et al., “Infantile Myofibromatosis,” Cancer 48:1807-1818 (1981)). Soft tissue lesions usually arise during childhood but can arise at any time during life and, intriguingly, can regress spontaneously. On the other hand, visceral lesions are associated with high morbidity and mortality (Wiswell et al., “Infantile Myofibromatosis: The Most Common Fibrous Tumor of Infancy,” J. Pediatr. Surg. 23:315-318 (1988)). The mechanism(s) underlying tumor growth and regression are not known. Some have suggested tumor growth to be linked to angiogenic stimulation and regression (Leaute-Labreze et al., “A Self-healing Generalized Infantile Myofibromatosis with Elevated Urinary bFGF,” Ped. Derm. 18:305-307 (2001)). Indeed, in a single case report, regression of an intracardiac IM was achieved through use of interferon alpha-2b (Auriti et al., “Remission of Infantile Generalized Myofibromatosis After Interferon Alpha Therapy,” J. Pediatr. Hematol. Oncol. 30:179-181 (2008)).
The genetic etiology of IM is unknown and both autosomal recessive (“AR”) and dominant (“AD”) patterns of inheritance have been reported. Consanguinity in a number of pedigrees has been interpreted to be in accord with an AR pattern of inheritance (Baird et al., “Congenital Generalized Fibromatosis: An Autosomal Recessive Condition?” Clin. Genet. 9:488-494 (1976); Salamah et al., “Infantile Myofibromatosis,” J. Pediatr. Surg. 23:975-977 (1988); Narchi, “Four Half-Siblings with Infantile Myofibromatosis: A Case for AutosomalRecessive Inheritance,” Clin. Genet. 59:134-135 (2001)). A large number of pedigrees, where affected individuals are identified across generations, are consistent with IM being an AD disease (Bartlett et al., “Multiple Congenital Neoplasms of Soft Tissues: Report of 4 Cases in 1 Family,” Cancer 14:913-920 (1960); Pfluger et al., “Kongenitale Polyfibromatose: Klinische and Genetische Untersuchungen,” Wiener Klinishe Wochenshrift 88:92-94 (1976); Jennings et al., “Infantile Myofibromatosis: Evidence for an Autosomal-dominant Disorder,” Am. J. Surg. Pathol. 8:529-538 (1984); Ikediobi et al., “Infantile Myofibromatosis: Support for Autosomal Dominant Inheritance,” J. Am. Acad. Dermatol. 49:S148-150 (2003); Zand et al., “Autosomal Dominant Inheritance of Infantile Myofibromatosis,” Am. J. Med. Genet. A. 126:261-266 (2004); de Montpréville et al., “Endocardial Location of Familial Myofibromatosis Revealed by Cerebral Embolization: Cardiac Counterpart of the Frequent Intravascular Growth of the Disease?” Virchows Arch. 444:300-303 (2004); Smith et al., “Infantile Myofibromatosis: Two Families Supporting Autosomal Dominant Inheritance,” Australas J. Dermatol. 52:214-217 (2011); Kulkarni et al., “Infantile Myofibromatosis: Report on a Family with Autosomal Dominant Inheritance and Variable Penetrance,” J. Pediatr. Surg. 47:2312-2315 (2012)).
The present invention is directed to overcoming deficiencies in the art.